Filter cartridge assembly for water treatment device

ABSTRACT

A filter cartridge end-of-life mechanism and a filter cartridge assembly for a water treatment device. The end-of-life mechanism comprises a float which is moved along an escapement path each time the device is filled. A counting mechanism connected to the float provides a continuous visual indication of the amount of useful life remaining in the filter cartridge. The cartridge assembly includes a tray detachably connected to a filter cartridge. The tray is positioned beneath the outlet end of the cartridge to remove water treatment particles from the treated water.

FIELD OF THE INVENTION

[0001] This invention relates to water treatment devices, such asgravity-fed devices, and to filter cartridges used in such devices. Inparticular, this invention relates to a fill-counting cartridge and acartridge assembly which removes water treatment particles from thetreated water.

BACKGROUND OF THE INVENTION

[0002] Domestic water treatment devices are known in the art. Theyinclude in-line devices (e.g., under the sink), terminal end devices(e.g., counter top or faucet mounted), and self-contained systems whichprocess water in batches. Examples of batch devices are pitchers/carafesand larger reservoirs where treated water is poured for example from aspigot. Batch water treatment systems can also be incorporated intoother devices, such as a coffee maker. These self-contained systemstypically have upper and lower chambers separated by a filter cartridge.They rely on gravity to force water from the upper chamber, through thecartridge, and into the lower chamber, thereby producing treated water.

[0003] Mechanical filters, which treat water by preventing particulatesfrom passing through them, provide a ready end-of-life indicationthrough reduced flow due to particulate accumulation. Chemical removalmedia (e.g., charcoal based media and ion exchange media) employprocesses such as adsorption and ion exchange for treating water. Theseprocesses do not reduce flow or provide other end-of-life indication.

[0004] Various approaches have been taken to provide end-of-lifeindication where it is not inherently provided by the media. It is knownfor example to “totalize,” mechanically or electronically, the volume ofwater that has been treated. The mechanical approach typically involvesa turbine and gear reduction mechanism. The electronic approachtypically involves a pressure transducer and a microprocessor whichintegrates to calculate volume. Such systems are relatively expensive,however, and do not lend themselves well to batch treatment devices.

[0005] In batch treatment systems, it is known to approximate the amountof water that has been treated by counting the number of times thedevice has been filled. Such a prior art device is described in U.S.patent application Ser. No. 08/341,420, filed Nov. 17, 1994, which isexpected to issue as a U.S. patent shortly. The '341 fill-countingsystem employs a float which rotates one revolution on a threaded rodeach time the device is filled. One short-coming of this approach isthat there is no continuous visual indication of the amount of usefullife remaining, but only an indication at the end of life.

[0006] Where relatively loose particle media are employed, such as theloose granular activated carbon and resins typically used in batchsystems, media particles tend to come out of the cartridge with thetreated water. Although ingesting these particles is generally not asignificant health concern, consumers consider it undesirable to seewhat appears to be sediment in the treated water. An example of agravity-fed system where this is a shortcoming is shown in U.S. Pat. No.4,969,996.

[0007] What has been needed is a novel fill-counting mechanism whichprovides a continuous visual indication of the amount of useful liferemaining in the filter cartridge. What has also been needed is a novelfilter cartridge assembly which reduces the number of media particles inthe treated water.

SUMMARY OF THE INVENTION

[0008] Certain aspects of this invention involve a filter cartridgeend-of-life mechanism for a gravity-fed water treatment device. Althougha carafe is shown herein, it will be understood that the invention couldbe employed in a variety of other gravity-fed devices, such as in alarger reservoir having a pour spigot or in a coffee machine.

[0009] In one aspect of the invention, the end-of-life mechanismcomprises a float which rises when the water treatment device is filled,and falls after the water has been treated. A counting mechanism countsthe number of times the water treatment device has been filled. Themechanism includes an escapement mechanism wherein the float is advancedalong an escapement path each time the float rises and falls.

[0010] In another aspect of the invention, the end-of-life mechanismcomprises a mechanism for counting the number of times the watertreatment device has been filled. The fill-counting mechanism includes amember which is moved by the water. A visual indicating mechanismcooperates with the fill-counting mechanism to provide a continuousvisual indication of the amount of useful life remaining in the filtercartridge.

[0011] In certain other aspects of the invention, the inventioncomprises a filter cartridge assembly which reduces water treatmentparticles in the treated water. Although a gravity-fed system isdisclosed herein, the invention could also be employed in systems wherethe water is forced through the media by other than gravity.

[0012] In another aspect of the invention, the invention comprises afilter cartridge assembly for a water treatment device. The assemblyincludes a filter cartridge containing water treatment material andhaving an upper inlet end and a lower outlet end. A tray is positionedbeneath the lower outlet end. It is detachably connected to the filtercartridge and separable from the water treatment device. The tray isconstructed and arranged so that treated water flowing from the outletend flows generally toward the inlet end and out of the tray. The trayholds particles of water treatment material coming from the outlet end,thereby making the treated water flowing out of the tray substantiallyfree of the particles.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A preferred embodiment of the present invention will be describedwith reference to the accompanying drawings, wherein like referencenumerals identify corresponding parts:

[0014]FIG. 1 is an exploded perspective view of a water treatment deviceaccording to the present invention;

[0015]FIG. 2 is a cross-sectional view of a filter cartridge, includingan end-of-life mechanism, according to the present invention;

[0016]FIG. 3 is a schematic diagram of an escapement path according tothe present invention;

[0017]FIG. 4 is a top view of the filter cartridge end-of-life mechanismshown in FIG. 2, taken generally along line 4-4 of FIG. 2; and

[0018]FIG. 5 shows a cross-sectional view of a filter cartridge assemblyaccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] The filter cartridge 10 described herein can be used in a varietyof gravity-fed water treatment devices. Filter cartridge 10 is shownherein in a carafe 100 by way of illustration. Referring to FIG. 2,cartridge 10 includes mechanism 20 which counts the number of times thatthe water treatment device has been filled. While fill-countingmechanism 20 is shown incorporated in filter cartridge 10, it could alsobe employed separately from a filter cartridge and therefore reused.

[0020] Fill-counting mechanism 20 includes float 25 which is advancedalong an escapement path each time the water treatment device is filled.Float 25 includes a plurality of downwardly extending annular walls 26which form channels 27 beneath float 25. Channels 27 trap air so as tocause float 25 to rise when it is submerged.

[0021] An “escapement” is a mechanism by which a member is advancedalong a path (usually circular) through a repeated movement between twodiscreet stopped positions. An example of an escapement path can befound in a pendular clock. Escapement paths other than that describedherein could be used within the principles of the invention. Forexample, the escapement path could be linear instead of circular. Also,as with the pendulum of a clock, the member moving between two discreetpositions need not be the same member which is advanced along theescapement path. The shape of the escapement path could also bedifferent from the saw-toothed path described herein.

[0022] The preferred escapement path 30 comprises upper 33 and lower 37paths formed in upper 32 and lower 36 escapements, respectively. As bestshown in FIG. 3, upper 33 and lower 37 paths are generally saw toothedand offset from-one another.

[0023] Float 25 advances along escapement path 30 as follows. Referringto FIGS. 2 and 3, as float 25 rises along center post 28, pin 29 (thepreferred float includes a plurality of pins) is raised from first tooth38 of lower path 37 (position A) to first tooth 34 of upper path 33(position B). Pin then travels along first tooth 34 from position B to Cas float 25 rises further. When float falls, pin 29 drops to secondtooth 39 of lower path 37 (position D) and further to position E. Thus,each time float 25 rises and falls, it is advanced one tooth alongescapement path 30.

[0024] Fill-counting mechanism 20 provides a continuous visualindication of the amount of useful life remaining in filter cartridge 10as follows. Referring to FIGS. 2 and 4, gear 24 on float 25 engagesplanetary gear 22 which is advanced in a circular path along teeth 31 ofupper escapement 32 as float 25 rotates. Planetary gear 22 includes stem23 which is visible through one or more openings 41 in cover 40.Planetary gear 22 travels clockwise (see arrow in FIG. 4) until itreaches stop 35 in upper escapement 32. Appropriate indications areprovided on cover 40 to tell the user when for example one-half of thecartridge life is remaining and when it has reached end of life.

[0025] A variety of continuous visual indicating mechanisms other thanthat disclosed herein could be employed within the principles of theinvention. For example, the mechanism could employ a member moved by thewater, such as a paddle wheel, which is not a float. An indicatingmember could be connected to the member which is moved by the water invarious ways. The mechanism also need not involve an escapement path.

[0026] Water flows through filter cartridge 10 as follows. Water entersthrough openings 41, 43 in cover 40 and lower escapement 36,respectively and through circular inlet holes 42 in upper escapement 32to fill float chamber 21. Downwardly protruding ribs 45 are provided onupper escapement 36 in order to break the surface tension between upperescapement 32 and float 25 when the water level drops, thereby assuringthat float 25 will fall. The water proceeds from float chamber 21through slots 46 at bottom of lower escapement to media 12. Water alsodirectly enters media 12 through slots 44, which are provided in thelower portion of lower escapement 36 so that substantially all of thewater in the upper chamber of the water treatment device enters filtercartridge 10. Treated water then exits filter cartridge 10 from slots 15in the bottom of housing 14.

[0027] A filter cartridge assembly 50 according to the present inventionwill now be described with reference to FIGS. 1 and 5. It will beunderstood that although assembly 50 is shown incorporated in a carafe100, it could also be employed in a variety of other water treatmentdevices within the principles of the invention.

[0028] Filter cartridge assembly 50 is shown in FIG. 1 in carafe 100.Carafe 100 includes funnel 105 forming an upper chamber for contaminatedwater and a pitcher 102 forming a lower chamber for treated water.Pitcher 102 includes handle 103 and pour spout 104. When carafe 100 isassembled, funnel 105 is inserted into pitcher 102 and cover 101 isplaced on top.

[0029] The preferred filter cartridge assembly 50 is shown in FIG. 5.Assembly 50 includes filter cartridge 10 and cup 55 releasably attachedto cartridge 10 by three inwardly facing protrusions 56, spaced at 120°intervals, which snap fit into corresponding detent 16 in cartridge 10.Cartridge 10 is sealed to downwardly extending sealing surface 106 offunnel 105 by an appropriately elastic sealing lip 17 around theperimeter of the upper end of housing 14. Channel 54 of cup 55 isreceived in recess 13 in filter housing 14. Key 107, which in turn fitsinto channel 54 of cup 55, is for the purpose of properly aligning cup55 and cartridge 10 relative to funnel 105.

[0030] Cup 55 is constructed and arranged to prevent particles of watertreatment media 12 from entering the lower chamber (here, pitcher 102)of the water treatment device. This is particularly a concern ingravity-fed devices, where loose media particles such as granularactivated carbon and ion exchange resins are employed. Contaminatedwater entering upper inlet end 18 expels media particles 12 from loweroutlet end 19 and into bottom 59 of cup 55. The particles are held inbottom 59 of cup 55 as treated water passes upwardly. Treated waterflows out of cup 50 through gap 51 between inside wall 52 and outsidewall 53, which acts as a deflector plate to direct the treated waterdownwardly. Notch 58 assists this flow by reducing the surface tensionof the water with the underside of bottom 59 of cup 50. Where the watertreatment device is a pitcher 102, gap 51 is preferably located on thesame side as handle 103 to keep particles from coming out of cup 55 whenpouring.

[0031] In this way, cup 55 acts as a tray which prevents media particlesfrom entering pitcher 102. When it is time to replace filter cartridge10, cup 55 can be removed, rinsed, and reattached to the next filtercartridge. Cup 55 could be constructed in a variety of other ways withinthe principles of the invention to beneficially reduce the amount ofmedia particles in the treated water.

[0032] It should be understood that the present invention is not limitedto the preferred embodiment discussed above, which is illustrative only.Changes may be made in detail, especially matters of shape, size,arrangement of parts, or material of components within the principles ofthe invention to the full extent indicated by the broad general meaningsof the terms in which the appended claims are expressed.

We claim:
 1. A filter cartridge end-of-life mechanism for a gravity-fedwater treatment device, comprising: a float which rises when the watertreatment device is filled, and falls after the water has been treated;and means for counting the number of times the water treatment devicehas been filled, including an escapement mechanism wherein said float isadvanced along an escapement path each time said float rises and falls.2. A filter cartridge end-of-life mechanism according to claim 1,wherein said float rotates about a center along a generally circularescapement path.
 3. A filter cartridge end-of-life mechanism accordingto claim 1, wherein said escapement path includes upper and lowergenerally sawtoothed paths which are offset from one another, such that,when said float rises it is raised from a first tooth of said lowerescapement path and travels along a first tooth of said upper escapementpath, and when said float falls it engages a second tooth of said lowerescapement path, thereby advancing said float.
 4. A filter cartridgeend-of-life mechanism according to claim 1, wherein said float includesat least one protrusion extending therefrom to engage said escapementpath.
 5. A filter cartridge end-of-life mechanism according to claim 1,further including means for providing a visual indication of when thefilter cartridge has reached the end of its useful life.
 6. A filtercartridge end-of-life mechanism according to claim 1, further includingmeans for providing a continuous visual indication of the amount ofuseful life remaining in the filter cartridge.
 7. A filter cartridgeend-of-life mechanism according to claim 6, wherein said continuousvisual indicating means comprise an indicating member advanced by saidfloat as said float is advanced along said escapement path.
 8. A filtercartridge end-of-life mechanism according to claim 7, wherein saidindicating member is a gear which engages corresponding teeth on saidfloat, such that, as said float rotates along said escapement path, saidfloat advances said indicating gear in a generally circular path, aportion of said indicating gear being visible to provide a continuousvisual indication of the amount of useful life remaining in the filtercartridge.
 9. A filter cartridge end-of-life mechanism according toclaim 1, wherein said end-of-life mechanism is incorporated into thefilter cartridge.
 10. A filter cartridge end-of-life mechanism for agravity-fed water treatment device, comprising: means for counting thenumber of times the water treatment device has been filled, including amember moved by the water; and means, in cooperation with saidfill-counting means, for providing a continuous visual indication of theamount of useful life remaining in the filter cartridge.
 11. A filtercartridge end-of-life mechanism according to claim 10, wherein saidmember is a float.
 12. A filter cartridge end-of-life mechanismaccording to claim 11, wherein said fill-counting means comprise anescapement mechanism wherein said float is advanced along an escapementpath.
 13. A filter cartridge end-of-life mechanism according to claim12, wherein said continuous visual indicating means comprise anindicating member advanced by said float as said float is advanced alongsaid escapement path.
 14. A filter cartridge end-of-life mechanismaccording to claim 10, wherein said end-of-life mechanism isincorporated into the filter cartridge.
 15. A filter cartridge assemblyfor a water treatment device, comprising: a filter cartridge containingwater treatment material and having an upper inlet end and a loweroutlet end; and a tray positioned beneath said outlet end, detachablyconnected to said filter cartridge and separable from the watertreatment device, said tray being constructed and arranged such thattreated water flowing from said outlet end flows generally toward saidinlet end and out of said tray.
 16. The filter cartridge assembly ofclaim 15, wherein said tray is shaped generally as a cup which extendssubstantially to said upper inlet end.
 17. The filter cartridge assemblyof claim 15, wherein the tray includes an outside wall extendingdownwardly to form a deflector plate and an inside wall extendingupwardly past a bottom end of said inside wall, such that the treatedwater flows out of said tray through a gap between said inside andoutside walls.
 18. The filter cartridge assembly of claim 15, whereinsaid tray includes a notch extending upwardly from a bottom of said trayto reduce the surface tension of the treated water on an underside ofsaid bottom.
 19. The filter cartridge assembly of claim 15, wherein saidtray is connected to said filter cartridge proximate an upper end ofsaid tray.
 20. The filter cartridge assembly of claim 15, wherein saidfilter cartridge assembly is constructed and arranged for use in and isincorporated in a gravity-fed water treatment device.